Do Ribbon Mics Need Phantom Power?

Audio professionals absolutely cherish ribbon microphones. Their vintage and warm sound along with a seamless frequency response are the few reasons behind that endearing love.

Like every other mic type, ribbon microphones too have their own unique features, requirements and limitations. A commonly asked question about them is: do ribbon mics need phantom power?

The simplest answer to it is ‘not really.’ Ribbon microphones are not always dependent on phantom power for their functioning. But sometimes, certain ribbon mics may need phantom power.

A straightforward answer without a story isn’t that fun, really. 

So let’s dive into the specifics of ribbon mics to understand why they don’t require phantom power. I’ll also talk about the instance when they seek phantom power.

A Little About Ribbon Mics

A ribbon mic uses a thin metallic strip that hangs between two magnets. The name ‘ribbon’ comes from that very delicate metallic strip that is also known as ‘ribbon.’

Whenever a sound wave touches the metal strip, it starts to pulsate in the magnetic field created by the two magnets surrounding it. Its vibration generates an electric signal which the mic captures and magnifies.

These mics are well-known for having a bidirectional polar pattern. Also referred to as a ‘figure-eight pattern’, a bidirectional pickup pattern allows a mic to capture sound equally, both from the front and back.

Yes, this means a ribbon microphone will effectively pick sound from its front and rear. At the same time, it also blocks the off axis sound approaching it from the other sides. As a result, a ribbon mic displays unique sensitivity to sound sources lying in two extreme directions.

But what about its connection with phantom powering? Let’s dig into that next.

So Does a Ribbon Mic Need Phantom Power?

Well, no! A ribbon mic does not inherently need phantom power to function. Quite often, the application of phantom power to a ribbon mic directly can even harm the metallic strip.

But why is it that these mics do not need phantom powering? To figure that, first let’s quickly recap what phantom power is.

Brief Insight into Phantom Power

Phantom power refers to an approach to provide electric power to mics. Typically, it is around +48 volts DC. It polarizes a mic’s internal capacitor which enables them to operate. The operation then produces electrical signals.

Generally, condenser microphones require phantom power which is supplied to it via an xlr cable attached to a preamp. A ribbon mic and dynamic mic do not really need phantom power as both of them generate electrical signals on their own. If you’d like to know more about the origins of phantom power and its connection with dynamic mics, read it here.

Coming back to ribbon microphones, let’s take a look at why they don’t demand phantom power as such.

Why Don’t Ribbon Microphones Need Phantom Power?

Ribbon mics including the vintage ribbon microphones don’t rely on phantom power for their operation due to the following reasons.

They Have Passive Operation

Ribbon microphones operate using passive electromagnetic induction instead of active electronic setup. In terms of their internal electronics case, they are similar to dynamic microphones. 

The process of sound waves crashing with the ribbon and its pulsating movement creating electrical signals is passive in nature. This basically means that they don’t need an external force to generate the electrical charge and signal.

They Have Low Output Resistance

Ribbon mics have weak output impedance (resistance). Low output resistance means they generate quite a powerful signal without requiring supplementary amplification. 

As a result, you can directly interface a ribbon mic with an audio interface or mic preamp without using phantom power to boost its signal.

They Have a Potential Risk of Impairment

Using phantom power with a ribbon mic comes with potential damage hazards. Phantom power is quite strong, and can injure the metallic ribbon.

Usually, phantom power of around +48 volts (DC voltage) is used with condenser mics. While this voltage doesn’t harm the condensers, the extra gain is potentially damaging for ribbon mics.

To sum it up, ribbon mics don’t seek phantom power’s support to work. They are quite self-sufficient otherwise. This is true for both active and passive ribbon microphones.

Quick Dive into Active & Passive Ribbon Microphones

A passive ribbon mic does not comprise active electronics like a built-in preamp or transformer, in its design. It relies on the ribbon and electromagnetic induction for generating electrical signals.

Moreover, passive ribbon mics are simpler in design, and have a natural and transparent sound reproduction. Their output level is also lower than active ribbon mics.

On the other hand, an active ribbon microphone uses active electronics like a built-in preamp or impedance converter. Its active components amplify its output level that makes it compatible with diverse audio interfaces and preamps.

Some active ribbon mics also provide features like low self-noise, high output levels and increased frequency response in contrast to passive ribbon mics. That said, the inclusion of active electronics tends to change the mic’s sound characteristics. The ‘less natural’ sound you may get from an active ribbon microphone is due to this reason.

It is established then that ribbon mics don’t need phantom power. Remember, I mentioned earlier in the article that certain kinds of ribbon mics may require phantom power. So what kind are they?

What Kind of Ribbon Mics Need Phantom Power?

Majority of ribbon mics including their passive and active types don’t depend on phantom power. Having said that, some contemporary ribbon mics, particularly those that utilize active electronics may need phantom power for their optimal functioning.

Generally, a passive ribbon mic may never need phantom power. But its active counterpart may have to rely on phantom power. The requirement of phantom power even for active ribbon microphones depends largely on that particular mic’s manufacturing company.

Manufacturing companies do clearly mention if a ribbon mic requires phantom power. Make sure to look for that mention on your ribbon mic’s packaging before using it.

In case you do use phantom power with your ribbon microphone, there are some precautions you’d need to exercise.

Safety Precautions to Use Phantom Power with Ribbon Microphones

Whenever you use a ribbon microphone with a preamp or mixer that generate phantom power\, take care of the following:

• Turn off the phantom power on any other device (excluding the preamp or mixer supplying it with phantom power) attached to the mic. With this measure, you prevent any damage hazards.
• Use dedicated ribbon microphone preamps that provide appropriate gain without damaging the mic. 
• Even when you use a dedicated preamp, handle your mic with extra care. Position and transport them very gently to avoid any unnecessary impact or air blast.
• When you get preamps for your microphones, be those condenser mics or ribbon mics, check their quality and reviews. Good quality preamps will likely have positive reviews. Thoroughly check their reviews, consult the potential preamps you want with an expert, and then make your decision.

Take care of these tips, and your ribbon microphone will stay safe even in the existence of phantom power.

The Verdict

By now you must be clear on the relation between phantom power and a ribbon microphone. The latter isn’t dependent on the former for its operation. 

In some cases, certain ribbon microphone variants do demand phantom power. If that’s the case, make sure to handle your mic carefully and strictly follow the instructions on its manual. Lack of proper care can damage your mic too.

Frequently Asked Questions